#include<iostream>
using namespace std;
int main(){
int s;
cout<<"你考试考了多少分？"<<endl;
cin>>s;
int a;
a=s/10;
if(a>=0&&a<=10)
{

switch(a)
{
case 0:
case 1:
case 2:
case 3:
case 4:
case 5:cout<<"差";break;
case 6:
case 7:cout<<"中";break;
case 8:cout<<"良";break;
case 9:
case 10:cout<<"优";break;

}
}
 return 0;
}